1. Field of the Invention
The present invention refers to apparatus for agricultural use. More particularly, it refers to an implement for the harvesting of seed-producing plants which is adapted to be connected to a mechanical harvester.
2. Prior Art
Certain seed-producing plants are difficult to harvest with mechanical harvesters because the seeds are produced either in spikes or in capsules and when they are ripe they are so weakly connected to the stalk that a relatively slight jarring, such as caused by the sudden contact with the harvester is sufficient to detach the seed. This is particularly true with respect to the sesame plant.
Moreover there is known the importance which this oil-bearing plant has in the edible-oil producing industry, since its yield is substantially greater than that of other oil-bearing plants of the type of peanuts, sunflower, etc. However, despite the excellent yield, its use has not become widely introduced to the extent which would be desirable, due to the above-mentioned difficulty in harvesting it mechanically and because it is necessary to effect its collection by hand, thus increasing its cost of production.
Insofar as known, there are no special implements for harvesting sesame and other seed-producing plants of the same or similar type. Modification of implements for the harvesting of other types of grains has not given the desired results since, on the one hand, the impacts produced on the plants are excessively violent and cause them to lose an extremely high percentage of their seeds and on the other hand no means have been provided to reduce to a minimum the loss of said detached seed, collecting it in its great majority before it can reach the ground and be lost.
Neither the spiked-tooth harvesters, provided with the sharpest blades, nor the disk harvesters as well as edge or sawtooth harvesters have achieved good results. In the first case, the blow itself necessary to effect the saw cut is already sufficiently pronounced and sudden to produce a shaking of substantially greater intensity than that necessary in order to loosen the seed of the sesame. In addition, as a result of this blow, the strong oscillation imparted to the plants has the result that the loss of seeds does not take place in the manner of a simple action of loosening them at the foot of the plant or in its vicinity but has scattering effects which cause the seeds to fly a considerable distance from the plant from which they have been detached. Accordingly, in this type of harvester it is extremely difficult to provide means which can collect the detached seeds. The same effects have been found with cutting disks of the sawtooth type in which the frequency of the blow transmitted to the stalk before being cut is in direct relationship to the number of teeth which have struck against it during the cutting, effecting in this case the beating in the manner of a vibration which, although it does not have as pronounced effects with respect to scattering, does have them with respect to the number of seeds detached.
Another important source of loss of seeds is the fact that in the traditional harvesters the cutting stations are generally preceded by guide devices in the form of spears or the like which protrude forward from the harvester and the purpose of which is to direct the plants toward each of the cutting stations located directly at the end of said spears. Although the effectiveness of this type of device is acceptable for plants which are not capable of losing seeds, in the case of sesame good results are not obtained since an appreciable number of plants strike violently and directly against the spear before being deflected from their position to each of the related cutting stations. This impact, of course, will result in the loss of seeds so that upon arrival at the cutting station the plant will be practically free of seeds, having lost them in the shaking preceding the cutting in front of the spear, first of all, and in front of the cutting device afterwards.